Door latch



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DOOR LATCH Original Filed Nov. 13, 1939 3 Sheets-Sheet 2 April 25, 1944.

Original Filed Nov. 13, 1939 j r l Ill/A9 '1, Pf/ g; ff g A. DIEMER DOORLATCH 3 Sheets-Sheet 5 Patented Apr'. 25, 1944 DOOR LATCH Anton Diemer,Stuttgart, Germany; vested in the Alien Property Custodian Originalapplication November 13, 1939,` Serial No.. 303,977. Divided and thisapplication 0ctober 10, 1940, Serial No. 360,523. In Germany May 12,1938 13' Claims.

This application is a division of application Serial No. 303,977, filedNovember 13, 1939.

This invention relates to door latches, especially for doors of motorvehicles and for other doors which when closed are under spring tension,the bolt of such-latches carrying out, in addition to its forwardmotion, also a transverse one or a cross motion. An object of suchdouble motion is to secure an easyv entering of the head of the latch-bolt into the striker plate or behind the lockingwedge, despite thedoor being distorted orv being under spring tension when in closedposition. This should occur prior to the door being completelyintroduced into the body frame, so that such doors need not be slammed.However, since with latches ofknown structure the bolt performs boththese movements simultaneously, the results aimed at are not alwayssecure- 1y attained. This is dueto the fact thatespeciallywith boltshaving their forward moticnfdepending upon spring action only t-mayoccur thatY the head of the bolt will not enter sufficiently deep intothe striker plate opening or behind the locking wedge, being thereonjammed in the attained position on account of great friction orpressure. In such a condition the door may open accidentally upon theoccurrence of the slightest concussion or distortion.

The present invention has for its object to remove Vthis drawback, :thisbeingv achieved by a suitable connection between the door handle and thelatch bolt providing for both said movements being carried outconsecutively only. In this way when alatch is to be unlocked, the boltperforms at first a cross motion only, whilst it is retracted into thevlatch casing after said cross motion is terminated. In lockingoperation, on the contrary,.the bolt executes first its forward motion,whereafter when this latter is terminated, it ,carries out its crossmotion providing for a complementary drawing of the door into the doorframe.

Another object is to provide two separate independently.operatingA doorvhandles on opposite sides of the door.

With these objects in View, in a preferred embodiment of this invention,I provide a slider betweenthe latch bolt and a lever connected to thedoor handle, said slider being .adapted to bear on thelatch bolt and .onthe latch casing. When the door handle performs an unlocking movementsaid slider first slides along a Wedge surface whereafter it causes thelatch bolt to perform its inwardmovement. Thejust mentioned wedgesurface may be arrangedeither `on' the bolt or on the door casing orontheslider proper.

When this door latch, is used with motor vehicles it is desirablel thatthe outer vdoor handle be able to .be moved independently ofthe innerone, so that, e. g., the inner door handle vremains stationary when thelatch is. o.pened by means of the outer door handle and vice versa. Inorder that such a mutualindependence ofboth vdoor handles be obtainedwith` the above ydescribed new door latch, I provide, laccording to afurther, improved-feature of this my invention between the latch boltyand the displaced doorhandles or respectively betweena slider actingyon the latch bolt and said doorhandles, a .swinging lever transferringthemotionbf the door handleeither to thelatch bolt, or tothe. slider. Bythis means when one of the door handles isrotated,.the point of.engagement .between the other door handle and .the swinging lever,servesv always asstationary fulcrum for said lever.

vOther featuresV and objects 4of the invention will more fully appearfromthe vfollowing description of a number of exemplary lembodimentsrthereof with reference to the appended drawings.

In the drawings:

Figures 1 to 5Villustrate one form of embodiment of a latch constructed,according to this my invention, wherein both .door handles operateindependently of one another.

Figures 6 to 9 illustrate a further exemplar embodiment of a latchhaving mutually independent door handles, and

. Figures`10 to 13 illustrate another exemplary embodiment of astructure analogous to the above mentioned ones.

In the exemplary embodiment represented on Figs. l to 5fboth doorhandles', 65, 66 the axles whereof are Amutually'displaced may beoperated independently one from another. 5 are views of the latch havingthe cover plate of its easing removed. v Fig. 1 illustrates the parts ofthe latch in their position of rest, Fig. 3 the same parts in anunlocking position obtained by a depression of the inner door handle B5,Yand Fig. 5 represents the parts of the 'latch in-their unlockedposition due to'a depression of the outer door handlel. Figs. 2 and 4are sectional views taken on lines 2-2 and 4-4 respectively of Figs. 1and 3.

In this embodiment the bolt 30 is mounted shiftably in longitudinaldirection in4 a chamber 35 of vthe latch casing and'it is arrangedyswingably about its reinforced-portion 36. The bolt 39 is held againstmovement in downward direc- Figs. l, 3 and` tion by means of its head 34sliding in an aperture 11 of the latch casing as well as by means of alug 19 of the cylindrical portion 36 sliding in a slit 18 of the baseplate 33 of said latch casing. The leaf spring 43 presses the bolt 38,when no other greater forces are acting thereon, toward the base plate33 of the latch casing. In this instance the roller 58 is mounted in thelatch bolt and the inclined surface 1| causing the bolt to move intransverse direction is arranged on the slider 55. This latter is guidedby a rectangular projection 54 engaging in the slit 18 of the base plate33 of the latch casing in parallelism to the direction of movement ofthe latch bolt 38. Said slider carries on its inner bifurcated end 88 aswinging lever 82 pivotally mounted on a pin 8|. A contraction spring 84attached to the base plate of the latch casing by means of a pin 83urges the latch bolt into its locked position. The cut-out 14 of thelatch bolt wherein the slider 55 moves has its aperture directeddownwards. The purpose of such arrangement is to enable the swinginglever 82 to pass through said cut-out. Therefore, the latch bolt head 34is connected in that case with the cylindrical portion 36 of the bolt bymeans of an upper arm 31 only.

A hub 85 mounted rotatably in the latch casing is positively connectedto the outer door handle 65'by means of a square shank 86 of said handlebeing inserted into the hub. Said latter carries rigidly connectedthereto and arranged in the latch casing a lever 81 also pivotallyconnected by means of a link 98 mounted on pins 88, 89 with the bottomend of the swinging lever 82. A contraction spring 92 attached to thelatch casing by means of a pin 9| causes an extension 93 of the lever 81to bear upon a striker stud 94 secured in the latch casing. An innerdoor handle 66 is positively connected by means of a square shank 96 toa second hub 95 also rotatably mounted in the latch casing. Said innerdoor handle is connected by means of a link 98 and a lever 91 attachedto the hub 95 with a point lying between the ends of the swinging lever82. This connection is of a similar linked nature as that of the outerdoor handle 65 with the bottom end of said swinging lever. The lever 91is drawn in its position of rest towards a stationary abutment pin |8|by means of a contraction spring |88 engaging with its extension 99.

If lever 61 is now moved upwardly by depressing the inner door handle66, it draws first the slider 55 by means of a link 98 and of a swinginglever 82 so far in backward direction that the inclined surface 1| ofsaid slider moves through beneath the roller 58 of the latch bolt. Thelatch bolt is thereby swung due to the action of leaf spring 43, aboutits cylindrical portion 36, towards the base plate 33 of the latchcasing. In this motion the pivot 89 of the link serves as fulcrum forthe swinging lever 82, so that the link 98 and the lever 81 form nearlya straight line when -in position of rest. On the other hand, thetraction forces transferred on the system 81, 98 when the inner doorhandle 66 is depressed the extension 93 of lever 81 with a greater forcetowards the striker stud 94, so that the outer door handle 65 remains inits position of rest when the latch is acted on by the inner door handle66. When the slider, as it has been explained above, is drawn back bylever 91 so far that its inclined surface 1| has entirely cleared theroller 58 of the latch bolt, said slider abuts by its bifurcated innerend 88 on the cylindrical movement it draws the latch bolt into thelatch casing up to the unlocking position represented in Figs. 3 and 4.When the latch is unlocked by the outer door handle 65, the movements ofthe slider and of the latch bolt 38 are carried out in the same sequenceas above,.with the only dierence that in said latter case the swinginglever 82 is turned by means of lever 81 and link 98 in clockwisedirection. Hereby also the pivotal connection |82 of the link 98 servesas relatively stationary fulcrum for the swinging lever 82 (see Fig. 5).

During the locking operation of the latch, both of the door handles and66 are also operated independently one from another so that any timewhen a door handle depressed prior to the door being closed performs anascendent movement it operates a tilt of the swinging lever 82 incounterclockwise direction. Simultaneously also the pivot pin of theother door handle engaging with the swinging lever acts as a fulcrum forsaid latter. By this means first of all the latch bolt is shiftedoutwardly together with the slider by the assistance of contractionsprings 84, 92 and |88 until said bolt strikes onto a pin |83 secured inthe lock casing whereafterV the slider 55 continues its outward movementalone until it reaches the position represented on Figs. 1 and 2.Following to this the inclined surface 1| of the slider enters betweenthe casing base plate 33 and the roller 58 of the latch bolt swingingthereby said bolt about its cylindrical portion 36. The head 34 of thelatch bolt is thereby forced against the abutment 18 of the lockingwedge 52, the inner surface 62 of the door being thus pressed to theyielding sealing strip 58. The force applied for this purpose on thedoor handle is relatively small, because the parts 91, 98 and 81, 98respectively act as toggle links which are nearly straight at the end ofthe closing movement of the latch bolt. It may be clearly seen from thedrawings that this embodiment of the latch maybe used for enabling thedoor to be closed by a mere slamming. In this case when the latch boltgets in contact with the inclined surface 15 of the locking wedge, it isshifted inwardly and on having passed said inclined surportion as of thelatch boit and at its further face it snaps back outwards again underthe action of spring 84, without thereby setting into movement theslider 55 and hence also the door handles 65, 66.

In the second exemplary embodiment provided with independently operateddoor handles as shown in Figs. 6 to 9 the latch is represented in lockedposition on Figs. 6 and 7. Fig. 7 represents a section of Fig. 6 takenon the line 1 1. Fig. 8 represents the latch unlocked by a depression ofthe inner door handle 66 whilst in Fig. 9 the same position of the latchbolt is shown after the outer door handle has been depressed. In all ofthe Figures 6, 8 and 9 each of which represents the latch in elevationthe cover plate 42 of the latch casing has been removed.

Broadly speaking, the details and the operation of this latch aresimilar to those of the above mentioned exemplary embodiment. But inthis case the levers 81, 91 moved by the door handles are not connectedto the swinging lever by links, such connection being made by means ofpins |88, |01 carried by levers 81, 91 respectively and engaging intopreferably arcuate slots |88, |89 of the swinging lever. Thus when lever81 is moved downwardly or lever 91 upwardly the swinging lever |85 isalways tilted in clockwise direction, a pin |86 or |81 of that amarresofthe levers S1, 91 which is not moved, serving thereby as a fulcrum forsaid swinging lever. A further difference vbetween this exemplaryembodiment and-the preceding one resides therein that in this case theroller-58 is arranged on the outer end of the slider 55, whilst thecambered vinclined surface 1| istformed on the head 34 of the latchbolt.

Another form of door latch according to this invention having lhandlesacting independently from .one another is represented in Figs. l0 to 13ci which`l'ig`. ilshowsagain the latch in locked position with thecoverplate 42 of the latch casing having been removed; Fig. '12,.is asection of Fig. l0 taken on the line l2-l2, whilst Fig. l1 representsin-.elevation a latch unlocked by the depression ofthe inner door handleSii and Fig. 13 :is a similar view of a latch having .been unlockedby a.depression of the outer door handle B5.

In'this exemplary. embodiment the swinging lever |1537' engages by meansof a cut-out provided on its upper end with a pin 8| ofthe slider. '55.On the bottom end of a Surface of the swinging lever` facing the baseplate 33 of the latch .casing a block ||2 is attached provided on. twoof its .sides with .gearing teeth. The upper` teeth ||3 of this blockengage with a segment i4 provided with corresponding teeth and;mountedto rotate on a stub shaft H5 secured in the base plate 33 of the latchcasing. In the same way the bottom teeth l I6 of part H2 are inengagement with ya, .toothed segment vrotatably.mounted on a stub shaftV| I8 also attached to the base plate .33.

TheY teeth H3 `and ||6 of the block H2 are formed .on curves facing oneanother. with their concavesides, the center of curvature ||9 of thearcoi- ,teeth H3 lying inthe point of contact ofthe pitch circle ofVteeth H5 ofthe block ||2 with the #pitch circle ofY the teeth ofsegment H1. `On the; contrary, the center of curvature |20 of the arcVof teeth HE of part |:|2 is located inthe point of contact of the Vpitchcircle of the-teeth H3 3f-part |12 with the pitchcircle of :the teeth ofsegment |14. Therefore, the swingingv lever l| Id `will rotateV aboutthe center of curvature H8 as-about a X'ed vfulcrurn in clockwisevdirection when the toothed segment H4 is rotated. in counterclockwisedirection.

Furthermore, Ythere will be also a clockwise rotationpfthe swinginglever H0, but this rotation is carried out` about the center ofcurvature liiil as aboutva xedfulcrum, when the toothed segmentil-is'turned in counterclockwise direction. Thetoothed segment i i4 isalso in operative engagement Awith another segment |2| rigidly mountedon `the rotary tumbler 95 of the inner dcorhandle 65, Whilst the toothedsegment. ,li'i engages with a further segment 22 rigidly mounted on therotary tumbler 85 of the outer door handle 5. Owing-.to the abovedisclosed arrangement, rwhen the inner door handle 66 is depressedtheswinging-lever i I U is turned about the center cf curvature ||9 inclockwise direction. By'this motion, in the same way as has beendescribed in connection with the precedent embodiments it retract-sprimarily into the latch casing the slider and thereafter also the latchbolt 3e. A similar unlocking operation is also present when on accountof depressing the outer door handle'the rswinging-lever Il@ is rotatedabout the center of curvature |20 in clockwise direction. On vthe otherhand, when both of the door handles are moved in upward' direction;

the parts of the latching mechanism move in opposite directions. Whenboth segments |2| and |22 are in their position of rest they are drawnrespectively by contraction springs |23 and |24 towards abutment pins|25 and |26 xed on the base plate of the casing. When the latch isunlocked by means of one of the door handles B5, Bt, the segmentbelonging to the other door handle is more strongly pressed against itsabutment pin by reaction forces acting thereon. In this way, theposition of one of the door handles is not inuenced by a depression ofthe other one, both vdoor handles being thus adapted to operate quiteindependently from one another.

Having described several illustrative embodiments of the invention it ispointed out that various changes and modificatonstherein may be madewithout departing from the invention, it being intended that `the patentshall cover, by suitable expression inthe appended claims, all featuresof patentable novelty existing in the invention disclosed, asillustrated by the embodiments described.

I claim:

l. A door latch of the kind described, comprising a casing adapted to besecured in a door, a latch bolt mounted slidably in said latch casingand adapted to be swung about its inner end in a direction transverse tothe plane of the door, a slider adapted to perform forward and backwardmovements along a base plate of said `casing between said plate and saidlatch bolt, a swinging lever pivotallyv connected with said slider andattached by link means to levers rigidly connected with hubs journalledin said latch casing and carrying spaced door handles adapted to beoperated independently from one another, each of said levers and itsrespective link being disposed substantially in a straight line when inposition of rest, and spring means adapted to urge said bolt into itslocking position and to press the head of said bolt towards a base plateor said latch casing.

2. A door latch of the kind described, kcornprising a casing adapted tobe secured in a door, a latch boit mounted slidably in said latch casingand adapted to be swung .about its inner end in a direction transverseto thefplane of the door, a slider adapted to perform forward andbackward movements along a base plate of said casing between said plateand said latch bolt, a swinging lever pivotally connected with saidslider and attached by link means -to levers rigidly connected withhubs' journalled in said latch casing and carrying spaced door handlesadapted to be operated independently from one another, each of saidlevers and its, respective link being disposed substantially in astraight line when in position of rest, spring means adapted to urgesaid bolt into its locking position and to press the head or" said bolttowards a base plate of said latch casing, said levers attached to hubsbeing connected in such way with two spaced points of said swinginglever that when one of said hub carried levers is swung by its doorhandle, said lever is rotated about the point of its pivotal connectionwith the lever carried by the other hub. v

3. A door .latch of the kind described, corn prising c ng adapted to besecured in a door, a latch bo mounted slidably in said latch casing andadapted to be swung about inner end in a direction transverse to theplane of the door, springrneans adapted to urge said bolt into itslocking position and to press the head ci said bolt towardsa base plateof said latch casing, a slider adapted to perform forward and backwardmovements along a base plate of said casing between said plate and saidlatch bolt, and adapted to retract said bolt into its unlockingposition, a swinging lever pivotally connected with said slider andprovided with oppositely curved slits engaged by pins carried on leversconnected with two diiferent hubs journalled in said latch casing andcarrying door handles, the curvature of said slits being preferablydirected in opposition to the curvature of the arcuate paths followed bysaid pins.

4. A door latch of the kind described, ccmprising a casing adapted to besecured in a door, a latch bolt mounted slidably in said latch casingand adapted to be swung about its inner end in a direction transverse tothe plane of the door, a slider adapted to perform forward and backwardmovements along a base plate of said casing between said plate and saidlatch bolt, a swinging lever having on one of its ends a pin and slotconnection with said slider and carrying on its other end two opposite'convexly arched toothed gear portions each of which is positivelyconnected by the intermediation of toothed gear members with one of thedoor handles, the centre of curvature of each one of said arcs of teethlying in the point of contact of the pitch circle of the opposite arc ofteeth with that of the intermediary toothed member engaging with saidopposite arc of teeth.

5. A door latch of the kind described, comprising a casing adapted to besecured in a door, a latch bolt mounted slidably in said latch casingand adapted to be swung about its inner end in a direction transverse tothe plane of the door, a slider adapted to perform forward and backwardmovements along a base plate of said casing between said plate and saidlatch bolt, a swinging lever movably connected with said slider, twohubs journalled in said latch casing and each carrying door handles,spring means adapted to urge said bolt into its locking position and topress the head of said bolt towards a base plate of said latch casingparallel with the plane of the door, and means operated by either hubfor actuating said lever.

6. A door latch of the kind described, comprising a casing adapted to besecured in a door, a latch bolt mounted slidably in said latch casingand adapted to be swung about its inner end in a direction transverse tothe plane of the door, a slider adapted to perform forward and backwardmovements along a base plate of said casing between said plate and saidlatch bolt, spring means adapted to urge said bolt toward its lockingposition, spaced door handles and connections between said door handlesand said slider for operating said slider either with or against theaction of said spring, upon operation of either door handle.

7. A door latch of the kind described, comprising a casing adapted to besecured in a door, a latch bolt mounted slidably in said latch casingand adapted to be swung about its inner end in a direction transverse tothe plane of the door, a slider adapted to perform forward and backwardmovements along a base plate of said casing between said plate and saidlatch bolt, spring means adap-ted to urge said bolt toward its lockingposition, spaced door handles and connections between said door handlesand said slider for operating said slider either with or against Cab theaction of said spring upon operation of either door handle, saidconnections each including a toggle linkage arranged to be substantiallystraight when the bolt is in elective position.

8. A door latch of the kind described, comprising a casing adapted to besecured in a door, a latch bolt mounted slidably in said latch casingand adapted to be swung about its inner end in a direction transverse tothe plane of the door, a slider adapted to perform forward and backwardmovements along a base plate of said casing between said plate and saidlatch bolt, spring means adapted to urge said bolt toward its 1ockingposition, spaced door handles and connections between said door handlesand said slider for operating said slider either with or against theaction of said spring upon operation of either door handle, saidconnections each including a toggle linkage arranged to be substantiallystraight when the bolt is in effective position, and each serving as anabutment for the reaction forces set up by operation of the other togglelinkage.

9. A door latch of the kind described, comprising a casing adapted to besecured in a door, a. latch bolt mounted slidably in said latch casingand adapted to be swung about its inner end in a direction transverse tothe plane of the door, a slider adapted to perform forward and backwardmovements along a base plate of said casing between said plate and saidlatch bolt, spring means adapted to urge said bolt toward its lockingposition, a rockable lever adapted to move said slider, spaced doorhandles and a connection between each door handle and said lever, eachconnection being adapted to rock said lever when actuated by its handle,and to provide a fulcrum for said lever when the other connection isactuated.

10. A door latch of the kind described, comprising a casing adapted tobe secured in a door, a latch bolt mounted slidably in said latch casingand adapted to be swung about its inner end in a direction transverse tothe plane of the door, a slider adapted to perform forward and backwardmovements along a base plate of said casing between said plate and saidlatch bolt, a swinging lever pivotally connected with said slider andattached by toggle linkages to spaced door handles adapted to beoperated independently from one another, each of said linkages beingdisposed substantially in a straight line when in position of rest, andspring means adapted to urge said bolt into its locking position and topress the head of said bolt towards a base plate of said latch casing,said linkages being connected in such a way to two spaced points of saidswinging lever that when one of said handle operated levers is swung byits door handle, said swinging lever is rotated about the point of itsconnection with the linkage connected with the other handle.

11. A door latch of the kind described, comprising a casing adapted tobe secured in a door, a latch bolt mounted slidably in said latch casingand adapted to be swung about its inner end in a direction transverse tothe plane of the door, a slider adapted to perform forward and backwardmovements along a base plate of said casing between said plate and saidlatch bolt, and arranged to force said latch to locking position, aswinging lever pivotally connected with said slider and provided withoppositely curved slots engaged by pins carried on levers connected withtwo different door handles, the curvature of said slots being preferablydirected in opposition to portions each of which is positively connectedby the intermediation of toothed gear members with one of two doorhandles, the center of curvature of each one of said gear portions lyingin the point of contact of the pitch circle of the opposite gear portionwith that of the intermediary toothed member engaging with said oppositearc of teeth.

13. A door latch of the kind described, com@ prising a casing adapted tobe secured in a door, a latch bolt mounted slidably in said latchcasing, a swinging lever having on one of its ends a pin and slotconnection for sliding said latch bolt and carrying on its other end twoopposite convexly arched arcs of teeth each of which is positivelyconnected by the intermediation of toothed gear members with one of twodoor handles, the center of curvature of each one of said arcs of teethlying in the point of contact of the pitch circle of t-he opposite arcof teeth with that of the intermediary toothed member engaging with saidopposite arc of teeth.

ANTON DIEMER.

